What is the maximum length of the tubing for suction type detectors?
The maximum length of tubing does not only depend on the strength of the pump, but also on the type of gas it is used for and the environmental conditions.
The long-life pump used by New Cosmos – BIE has a capacity of 0.5 liters per minute, which means if you do not bear in mind the above mentioned conditions, that at least 15 meters PTFE could be connected.
Even though PTFE does not react with gas, especially most acid gasses have the tendency to stick on the inside of the sample line. Depending on the humidity in the environment they will form a small layer on the inside of the sample tubing. Tests have revealed that 20 meters of PTFE sample line can create a loss of 28% when transporting 14 ppm of HCL. For this reason New Cosmos – BIE recommends to keep the sample lines as short as possible and have a close look at every application.